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Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic. Dr. M. Sc. Gintcho Kostov, Bulgaria “GEO ZEMIA” Ltd.
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Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic Dr. M. Sc. Gintcho Kostov, Bulgaria“GEO ZEMIA” Ltd.
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 1. Introduction Nowadays the current GNSS status: -provides high quality of the geodetic determinations -as the satellite modernizations continue -planning needed to obtain best overall quality results -some key moments should be discussed www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 2. Tasks of this paper To be analysed: – How much would be the improvement in the quality of the GNSS determinations by the created survey schedule? –Will the productivity be decreased? – Will there be a (significant) change in the values of the quality criteria between the “worst” and “best” time frames? www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 3. Possible ways to do planning of GNSS measurements Planning of satellite measurements 1. By the “classical” way - using the firmware, discussed here 2. By the “cloud” way – via the Internet Key moment – the applied parameters www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 4. PRACTICAL ASPECTS AND PARAMETERS OF THE GNSS SYSTEM Used methodology in the study: I. Type of the survey. Fast static mode was used. The spatial chords were chosen according to the following conditions: 1. Reference. One and the same reference point was used; 2. Lengths of the chords - up to 5km, up to 10 km, up to 20 km, up to 30 km. 3. Rovers. - Placed on points from the existing geodetic network (on close proximity to major roads), which have clear horizon. II. Previous experiments. Certain values of the parameters were applied in the GNSS system, according to author’s results and conclusions in other tests. III. Factors. For the practical implementation were taken into account the following key moments: 1. The safety - the measurements were conducted during daylight; 2 .The productivity - the length of the sessions was set to a reasonable amount of time; 3. The convenience - each rover was placed on point with easy access by car. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 5. CONDUCTED PLANNED GNSS MEASUREMENTS Four spatial chords were subject of quality assessment: 1. RT 22 (Kaloianovec) – length of 2.8 km. 2. GT 527 (Bogomilovo) – length of 9.1 km. 3. RT 1829 (KEN) - length of 17.4km. 4. GT 547 (Oriahovica) - length of 28.5km. The experiment was divided into four cycles of GNSS measurements: I. First cycle – Provides “best” quality conditions for chords “Kaloianovec” and “Oriahovica”. “Worst” conditions - for chords “Bogomilovo” and “KEN”. III. Third and fourth cycles – The chord “Bogomilovo” was studied using “best” and “worst” time-windows for GNSS measurements. II. Second cycle – Consists of “worst” quality conditions for chords “Kaloianovec” and “Oriahovica”. “Best” time-window for chords “Bogomilovo” and “KEN”. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 5. CONDUCTED PLANNED GNSS MEASUREMENTS Note: Under the term “the worst time-window in the day” should be understood a time-span when minimum number of satelliteswere visible and maximum value for GDOP was predicted. The term “the best time-window in the day” denotes a period of the day, when maximum number of satellites were visible and minimum value for GDOP was predicted. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 6. USED CRITERIA FOR OVERALL QUALITY ASSESSMENT OF THE CONDUCTED GEODETIC MEASUREMENTS In this study the following quality criteria were used: a) Quality in position and height ; b) Elements of the co-variance matrix for the chord: ; c) Number d) Number www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 7. PROCESSING OF THE QUALITY CRITERIA, USING FUZZY LOGIC Specific values of the parameters were applied The raw data was post-processed The rating - information for the overall quality of the measured chords Data entered in the specialized geodetic software Vienna_fuzzy The values of the quality criteria-calculated In this specific study, the bigger the value of the rating, the better the overall quality of the chords. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 7. PROCESSING OF THE QUALITY CRITERIA, USING FUZZY LOGIC Fig. 1 – Window from specialized geodetic software Vienna_fuzzy. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 8. ANALYSIS OF THE RESULTS The results - the rating values by Vienna_fuzzy for the overall quality assessment: • First cycle, Table 1 www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 8. ANALYSIS OF THE RESULTS II. Second cycle, Table 2 www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 8. ANALYSIS OF THE RESULTS III. Third and fourth cycles, Table 3 difference in rating - 0.07 – same overall quality www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 8. ANALYSIS OF THE RESULTS Based on the GNSS planning and according to the calculated rating values it could be summarized: I. First and second cycles a) Chords with lengths of 2.8 km. and 9.1 km.: The difference between the rating values is 0.03. It could be noted that the geodetic determinations have similar overall quality. b) Chord with length of 17.4 km.: The final result from the analysis - difference of 0.10 between the rating values. It denotes slight improvement in the overall quality of the chord. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 8. ANALYSIS OF THE RESULTS II. Third and fourth cycles The planned GNSS measurements for these cycles were conducted exclusively for a chord - up to 10 km. The rating values from third and fourth cycles differ with 0.07. No significant difference in the quality of the chord was observed for these cycles. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 9. CONCLUSIONS According to the results and analysis, it could be concluded that very small differences in the overall quality of each measured chord were calculated between the relevant cycles. The points to discuss, could be answered in the following way: – There is a small improvement in the overall quality of the chords between “the worst time-window in the day” and “thebest time-window in the day”. The difference in the rating is within the interval[0.03-0.1]. – The calculated values of the quality criteria for each chord and cycle vary. This was one of the main reasons to apply Fuzzy logic to produce objective results. – It should be noted, that the productivity was strongly decreased, as strict schedule for conducting of the measurements was used. For specific projects or when explicitly required, planning should be used in order to produce the maximum possible overall quality. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic 9. CONCLUSIONS According to the recent improvements of the IT in the GNSS, for geodetic applications, which do not require very high level of accuracy, planning may not give significant improvement in the overall quality of the results. It would decrease the productivity of the GNSS determinations. Future work and experiments could include study and analysis at places with existing obstructions in order to test their level of influence on the results from the geodetic measurements. www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic REFERENCES: Kostov, G. 2010. Assessing of the Overall Quality of GNSS Determinations, Using Specific Values of Parameters. Third International Conference on Cartography and GIS, Nessebar, Bulgaria. Kostov, G. 2007. Assessment of the Quality of Geodetic Networks Using Fuzzy Logic. Geowissenschaftliche Mitteilungen Heft Nr. 78. Pages 4-19. Wien. Schriftenreihe der Studienrichtung Vermessung und Geoinformation Technische Universitat Wien. ISSN 1811-8380. Kostov, G. 2010. Some Studies on the Quality of GNSS Determinations Under Specific Conditions. FS 1H - GNSS CORS Networks - Positioning Infrastructure, Analysis and Applications I. FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia. ISBN 978-87-90907-87-7. Kostov, G. 2009. Using of Fuzzy Logic for Some Studies over GNSS Determination in fast Static mode. University of Architecture, Civil Engineering and Geodesy. International Scientific-Applied Conference. Sofia, UACEG 2009. ISSN 1310-814X. Wellenhof, B., Herbert Lichtenegger, James Collins, 2002, GPS Theory and practice, Springer-Verlag/Wien, pp183, Wien, Austria (in Bulgarian). www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic REFERENCES: WEB: http://asp.ashtech.com/wmp/ http://en.wikipedia.org/wiki/GLONASS http://maic.jmu.edu/sic/gps/planning.htm http://www.ask.com/wiki/GLONASS#Renewed_efforts_and_modernization http://www.ewdn.com/2011/06/02/glonass-sets-goal-to-exceed-gps-accuracy-twofold-vice-pm-guarantees-free-service-worldwide/ http://www.gpsworld.com/survey/satellite-gps-glonass-sbas-mission-planning-8635 http://www.isprs.org/proceedings/XXXVIII/4-W13/ID_10.pdf www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic REFERENCES: WEB: http://www.navcomtech.com/Support/Tools/satellitepredictor/main.cfm http://www.navleader.com/GGE2012_LectureNotes/20.Lecture110322_GGE2012_GPS03_PlanningGPSsurvey_byAhn_2pages.pdf http://www.navleader.com/GGE2012_LectureNotes/21.Lecture110324_GGE2012_GPS04_Tutorial_byAhn_2pages.pdf http://www.oregon.gov/ODOT/HWY/GEOMETRONICS/docs/presentations/2-10-11_Olsen_Armstrong-Part4_GNSS_Survey_Planning.pdf?ga=t http://www.pods.org/assets/file/PODS_UserConference_FutureofHigh-AccuracyGPS_2011.pdf http://www.romdas.com/romdascd/info/faq/GPS%20Survey%20Planning.pdf?token=d3d4138d99e1556bdfb8cbbe8eb1260e99ffc63e|1328729771#PDFP http://www.trimble.com/GNSSPlanningOnline/#/Settings www.geozemia.com
Study on the Overall Quality of the Planned fast Static GNSS Measurements, if Certain Values of the Parameters are Applied in the System, Using Fuzzy Logic Thank you for your attention! www.geozemia.com